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hyphenrf's solution

to Matching Brackets in the OCaml Track

Published at May 06 2020 · 0 comments
Test suite

Given a string containing brackets [], braces {}, parentheses (), or any combination thereof, verify that any and all pairs are matched and nested correctly.

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Ginna Baker


open Base
open OUnit2
open Matching_brackets

let ae exp got _test_ctxt =
  assert_equal exp got ~printer:Bool.to_string

let tests = [
  "paired square brackets" >::
  ae true (are_balanced "[]");
  "empty string" >::
  ae true (are_balanced "");
  "unpaired brackets" >::
  ae false (are_balanced "[[");
  "wrong ordered brackets" >::
  ae false (are_balanced "}{");
  "wrong closing bracket" >::
  ae false (are_balanced "{]");
  "paired with whitespace" >::
  ae true (are_balanced "{ }");
  "partially paired brackets" >::
  ae false (are_balanced "{[])");
  "simple nested brackets" >::
  ae true (are_balanced "{[]}");
  "several paired brackets" >::
  ae true (are_balanced "{}[]");
  "paired and nested brackets" >::
  ae true (are_balanced "([{}({}[])])");
  "unopened closing brackets" >::
  ae false (are_balanced "{[)][]}");
  "unpaired and nested brackets" >::
  ae false (are_balanced "([{])");
  "paired and wrong nested brackets" >::
  ae false (are_balanced "[({]})");
  "paired and incomplete brackets" >::
  ae false (are_balanced "{}[");
  "too many closing brackets" >::
  ae false (are_balanced "[]]");
  "math expression" >::
  ae true (are_balanced "(((185 + 223.85) * 15) - 543)/2");
  "complex latex expression" >::
  ae true (are_balanced "\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2 \\end{array}\\right)");

let () =
  run_test_tt_main ("matching-brackets tests" >::: tests)
let are_balanced s =
  let bracks = Stack.create() in
  let compare s c = assert ((Stack.pop s) = c) in
  let parse = function
    |'(' |'{' |'[' as o -> Stack.push o bracks
    |')' -> compare bracks '('
    |'}' -> compare bracks '{'
    |']' -> compare bracks '['
    | _ -> ()
  in try 
    String.iter (fun c -> parse c) s; 
    if Stack.is_empty bracks then true 
    else false
  with _ -> 

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